This is why Heathkit failed.
If you've been following along, I built my own 30 watt per channel stereo audio amplifier, with a case. Twice, in fact.
While it did work out, you'd do well not to add up the cost:
The Velleman K4003 amp kit: $33.95.
24 VAC CT transformer: $13.95
Aluminum case: $21.00
Misc. parts: $10.00
Not including shipping and labor.